This issue still exists in the current latest drivers from October and November.
There is also a youtube video that demonstrates the issue at the 12:05 minute mark.
Thank you folks on AMD forums for at least pointing me towards identifying my problem.
I have this exact same issue, here's the thing.
I've just upgraded from a RX580 to a RX5700XT and I'm just now experiencing this issue with Adrenalin 2019 Edition 19.9.2.
I've always had freesync enabled on my RX580, but I never saw this issue before I upgraded.
I really don't wanna have to disable Freesync.
My main monitor is an AOC 35-144 hz and my TV is just a 60hz, running HDMI from GFX to a receiver and HDMI throughput from the receiver to the TV.
As far as I can tell, Vega's were the only ones affected by this bug, but I can now confirm that Navi's has it too
I read earlier that reducing Hz from 144 to sub-120 might help with the problem, I'll try that when I get home and report back.
But yeah, the youtube vids posted earlier shows exactly what I'm seeing with 5700XT also.
OK - Changing my main monitor to 120/100/60 hz. didn't do the trick.
I've messed around with all kinds of settings, but all to no avail.
As far as I can tell, a Windows update from last year caused the issue. One day I decided to update both Windows and the drivers for my RX 480 (didn't have the issue before that), and the issue appeared. I rolled back the driver to the one I know didn't have the issue, and even tried older drivers - but it still persists. Been keeping Freesync disabled since then. Currently still having the issue on my Vega 64 when I enable FreeSync.
I'm almost tempted to install an older version of Win10 or even run Win 8.1 on my system.